#include <stdio.h>
int main() 
{
    int a[4] = {0},i = 0,max = 0;
       for(i = 0;i<4;++i)
       {
        scanf("%d",&a[i]);
        if(a[i]>max)
           max=a[i];
       }
        printf("%d\n",max);
    
    return 0;
}
